"Religion" refers to a set of core beliefs upon which people base their lives. For Christians, religion includes all of logic plus the addition of faith. Morality has often historically been based on religion, but many movements such as the secular humanists hold that morality does not depend on religion, and secular views of morality have existed as far back as ancient Greece[1]. Beyond this general definition, the word "religion" is used in several ways:

Functional definition: "A cause, principle, or system of beliefs held to with ardor and faith"[4] By this definition, non-theistic belief systems such as atheism, humanism, and agnosticism could be considered religions. Indeed, the Supreme Court of the United States of America has acknowledged that "religion" does not need to include a belief in a god or gods, and included Secular Humanism as an example of a non-theistic religion.[5][6]

Organisational definition: Under the definition, the term refers to a particular religious organisation or movement, such a Catholicism, Methodism, or Lutheranism. These groups generally consist of a central creed or body of beliefs, an ethical component (i.e. a code of morals), a body of literature or holy texts or stories, and a set of individual and communal practices. Under this definition, a person might say, "I'm not religious, because I don't go to church—but I believe in God."

Practical definition: Under this definition, the term refers to a set of practices, rites, or rituals observed by followers. Under this definition, a person might say, "I'm not religious, because I'm not into rituals. My relationship with God is enough."

Monotheistic religions

Polytheistic religions

Polytheistic ("many gods") religions believe in and worship multiple gods or spirits or other supernatural beings. Polytheism has declined since the rise of Christianity, but has seen a recent resurgence among pagan cults in developed nations.

Pantheistic religions

It is also worth noting the existence of 'Panentheism' and the importance of distinguishing it from Pantheism. Panentheism is the belief that God is in all things and is chiefly manifest in Animism. Nonetheless, Pantheism and Panentheism have also been shown to feature in some outlooks generally defined as 'Monotheistic' (cf. Baruch Spinoza).

Non-theistic religions and philosophies

Non-theistic religions do not have a belief in God or gods. Some consider the existence of God to be unknown or irrelevant, while (strong) Atheism is the belief that asserts it is false.

Parody and joke religions

Several "religions" have been invented in an effort to denigrate or parody traditional religions. While most adherents of these "religions" are not serious believers, there are inevitably a few people who take the tenets seriously.

Faith in organised religion

The percentage of respondents answering they had a "great deal" or "quite a lot" of confidence in organised religion has decreased in the United States according to a Gallup poll taken in 2007. Only 46% of respondents selected either of the choices above. The numbers peaked at 68% in May 1975.[7]

Development of religion

Secular scholars and liberals, in order to justify their own postmodernist ideal that religious faith is a subjective issue, all religions are equally valid, there are no absolutes and consequently morality is relative, tend to take an evolutionary approach to the development of religion in human societies.

They usually suscribe to the idea that religion first started off as a primitive form of Animism or Spirit Worship, then evolved into polytheistic tribal/national religions, and then from one of these religions emerged Zoroastrianism which saw a gradual decrease in its number of gods until it eventually was transformed into a monotheistic religion, which in turn evolved into the well organized, theologically complex and philosophically deep monotheistic faiths of today such as Christianity, Judaism and Islam.

This idea regarding the development of religion continues to appear in liberal publications, despite the fact that it has little real substantiation and is merely an assumption by liberal scholars, who often hold a certain kind of prejudice towards organized religion.

In reality, the exact opposite viewpoint has more substantiating anthropological evidence. Namely, the viewpoint that Monotheism (faith in one sole creator deity) was the original form of religion, but gradually corrupted until it fragmented into various polytheistic religions, which in turn decayed further giving rise to pantheistic and atheistic religions.

For example, expert egyptologist Flinders Petrie suggests there is sufficient archaological evidence to conclude that the religion of the ancient Egyptians, which is normally categorized as a typical polytheistic religion, was not originally polytheistic, but in fact a monotheistic faith, which only in the later years of the Egyptian empire shifted from monotheism to polytheism.

similarly, doctor Steven Rangdon of Oxford University based on his research of ancient Babylonian inscriptions concludes that the ancient Babylonian religion like the ancient Egyptian religion was also originally monotheistic, and only in the later stages of the Babylonian civilization did it start to transform into a polytheistic and idolatrous religion. Interestingly, this was also the case with the ancient Sumerian religion. The Sumerians believed in over 5000 gods at the time of the end of their civilization. At the start of their history, however, they only worshiped one god, the god of the sky. It is more than likely that the Sumerian god of the sky is the same God of the heavens of the Hebrew Bible.

Interestlingly, this trend can also be seen in far Eastern religions. Shinto (神道), a native polytheistic religion of Japan which now believes in the existence of thousands of deities, was in fact originally a religion with only three gods. As time passed, however, the religion started to fall into a state of decay as believers started to arbitrarily created more and more new gods of their own. The further one goes back in Japanese history the number of gods in Shinto lessens significantly. In addition, some Japanese scholars, for example evangelical theologian Kubo Arimasa, postulate that it is possible that Shinto was in fact originally monotheistic, and the three originals gods decribed in the opening of the oldest known Shinto text Kojiki were, in fact, originally one creator God, identical to the creator of the Old Testament.

This monotheism → polytheism → pantheism religion curruption hypothesis is also in concordance with the scriptures of the Old Testament which tells explicitly that the origin of polytheistic, idolatrous and pagan religions was the rebellion of sinners who sought to free themselves from the laws of the true creator, the Lord Yahaweh.

↑"Among religions in this country which do not teach what would generally be considered a belief in the existence of God, are Buddhism, Taoism, Ethical Culture, Secular Humanism, and others.". Torcaso v. Watkins, (1961)

↑"A federal court of appeals ruled ... Wisconsin prison officials violated an inmate's rights because they did not treat atheism as a religion." Court rules atheism a religion WorldNet Daily